November 2012

Friday, 30 November 2012

Unplug it, and try to pull it free of the computer kennel: nope, not comin' outta there.

Workstation is due for a software update that looks like it'll call for a reboot. So:

Do the apt-get upgrade, and shut the workstation down.

Pull the workstation out, look behind it, and eventually find the other end of that HDMI cable.

Which has a DVI connector on it. Which (a) explains why it was so hard to pull through the cable clump, and (b) isn't exactly what I was looking for, but maybe will do.

So, pull the cable through the other way, and put everything back together.

Reboot the workstation.

Text display during bootup has colored sparklies.

DVI connection to back of workstation wasn't properly secured. With the jackscrews tightened, the sparklies go away.

Kdm thinks it starts up, but there's no X display.

Startx gives an error log that seems to say that it can't find a connected monitor.

OK, so re-configure the DVI cabling so the workstation's output goes directly to the monitor, bypassing the DVI switch (which isn't currently used anyway, what with the second workstation being retired).

Still doesn't work.

Boot the previous kernel: nope.

Fiddle around some more: still no soap.

About ready to panic here... has my software configuration gotten horribly broken? On the last day of the month, when I ought to be doing Accounts Receivable this evening? Will I have to use my laptop until I can get this sorted out?

Maybe if I boot some runs-from-CD distro...? Pop the April edition of Kubuntu into the drive, and tell the BIOS to boot from it.

Meanwhile...

Hey, wait. Could unplugging the HDMI cable have...

Once more unto the breach 'twixt desk and wall, narrow and cable-beclutter'd though it be.

Ah. I hadn't tightened the jackscrews on the DVI connection to the monitor, a couple of years back. When I unplugged the HDMI cable, I must have jostled it.

OK, tighten the jackscrews, reset the workstation in midKubuntuboot, and boot normally.

Well, looky here: kdm starts, and the X display comes up as normal.

And what I needed the HDMI cable for? Maybe I'll get to that tomorrow. Trying to diagnose some hardware that shouldn't need it, but maybe does.

Enough stress for now. Time for some mindless entertainment, assuming the living-room infosystems are still in working order.

Improve, presumably, energy density by a factor of five. Let's see... I don't have the number at my fingertips these days, but for a primary cell there's not much room for improvement on yer basic lithium coin cell. I recall doing the math on that one 'bout twenty year back, when working on a project to develop a small electronic gadget that would operate for a decade without anyone having to be aware that it had a battery (and using 1993 technology). Once we ruled out hydrazine-air fuel cells and RTGs, it looked like we were stuck with lithium as a safe-ish, self-contained energy store.

Tuesday, 27 November 2012

Got a largish topic in the queue, for some day when I have time, energy, and motivation, but....

Busy with work (various), family stuff (ditto), holiday-related disruptions (just when ya get done with one dang holiday, there's another one to prepare for), and seasonal crud (brought on by dry indoor air and early sunsets; even with the full-spectrum light on over my desk, I can tell that it's night out there).

And I failed to have a camera along last week when I encountered the Young Venison Stuffed With Bay Nuts (or at least stuffing itself with bay nuts), so no cute photo to post. No photos of the Dread Guardians of Farm and Forest, either. (The Dread Guardian of the Forest seems to be having trouble learning its line; it's good at striking a defiant pose astride the trail, but then instead of saying "None shall pass" it says "mew?", which is not at all a proper thing for a Dread Guardian to be saying.)

Oh. The GPIO on the 12-bit ADC models is wildly different from that on the 10-bit ADC models.

And, there don't appear to be sample projects for the newer line.

Grumblegrumble....

Oops. And pins 19 and 20 are now no-connects on the non-USB parts. At least I wasn't using those for anything vital. All the other pins seem to be in the right places. But... I'll need to re-do (or at least re-define) everything relating to GPIO and pin assignments.

Friday, 16 November 2012

(Low-fat Twinkies, however, are An Abomination Unto Nuggan, or at least Unto the Goddess. This was experimentally confirmed several years ago when someone tossed a low-fat Twinky* onto a fire as an offering, and it wasn't accepted. Just sat there amid the flames, and eventually started leaking a bit.)

Still kinda under the weather, between What's Going Around and the change of seasons, and spending unproductive time skimming through the Air Crash Investigation stuff.

Coupla examples of planes that crashed due to a blocked pitot tube, or taped-over static ports. (Taped over with plane-colored tape? Couldn't the plane-washing crew use fluorescent orange masking tape?)

And, yeah, those were several years ago. More recently, though: Air France 447 (airspeed sensor problem, followed by the pilot doing a Ben-Bernank at the controls), and that oh-so-modern stealth bomber that crashed due to an airspeed sensor problem. So the problem hasn't been fixed.

And yet: all the newfangled planes have GPS... which will happily provide you with pretty darn accurate readings for altitude and ground speed. Given even a vague notion of current wind, the computers can do a sanity check on the airspeed indicator, and coming up with the actual altitude (within several feet) should be a no-brainer.

True, knowing ground speed won't keep you out of coffin corner... but if you're high enough to be worrying about that, and you don't have an accurate airspeed indication, why not just be conservative about speed and angle of attack, and live with the loss of altitude for the nonce?

And, of course, if your pitot tube is blocked at takeoff, the computers bloody well ought to notice that indicated airspeed isn't keeping up with ground speed while you're still on the runway, and give a great big "critical flight instrument malfunction" warning while there's still time to abort the takeoff.

Update: hoo boy! Consider, further, Turkish Airlines Flight 1951. Pressure altimeter, GPS, and right-seat radar altimeter agree (taking local terrain into consideration): plane is about 2000 feet AGL. Left-seat radar altimeter claims 8 feet BGL. Stupid robot under the hood decides the plane is about to touch the runway, or has already landed, or perhaps is underground, and that in any case it's time to cut power, regardless of the pilot's opinions on the matter. One of several instruments gives a wrong reading, and it has the deciding vote. Brilliant!

Thursday, 15 November 2012

Well, learning LabVIEW has been on my gotta-do list for some time now, but I've been putting off the evil day by doing all my cute-GUI test-automation stuff in Ruby instead. I understand Ruby. It doesn't have a weird draw-a-picture-and-guess-what-it-means interface.

However... just started negotiating a likely Deal that (a) could develop into a long-term arrangement, and (b) pretty much requires using LabVIEW, in order to fit in with the client's existing automation.

So, something to learn during the rainy season, and I can probably use an evaluation copy for the purpose.

So, what's LabVIEW cost for real?

Yipe! $1K for the base version, which is Windows-only (the client is Windows-only, but I don't keep much in the way of Windows around here). For the full version that can run on Linux... starts at $2700. And for the development environment that'll compile your application to a .exe for distribution? Neighborhood of $5K. Or so.

Oh, and if you actually want to do useful stuff, like communicate with other applications? $$$KA-CHING$$$

Ruby, meanwhile, costs $0 for the development license and $0 for the runtime license, and is nicely cross-platform. And I can tell what it's going to do, 'cause I'm writing real code in a real language.

Oh, well: if I gotta have a LabVIEW development environment, I gotta price it into the business somehow. (Or, conventionally, come up with the business capital to buy the software up front, and trust that it'll help bring in enough additional business to cover the bill.)

Relatedly, I was thumbing through a catalog a few weeks back and happened across the pricing for µC/OS (which I assume is pronounced "mucus"). I'd had a vague notion it was pricey, given that the company was handing out free copies of the big heavy printed-on-paper manuals at a trade show not so long ago, but... really? Looks like the pricing strategy is "figure what it would cost to have Gumby develop it from scratch at his full consulting rate, and charge half that much for a single-product license."

These past few months, I've been getting an awful lot of bounce or delay messages, from unfamiliar hosts around the world, informing me of difficulty in delivering mail ostensibly from one or another of my addresses to, typically, one of the big free-email services.

I've been unsure whether these were actual bounces of spam on which my return address had been forged, or intentional reflectospam meant to be delivered to me disguised as bounce messages.

Either way, there must be a lot of misconfigured mail severs out there.

Sunday, 11 November 2012

Been watching some episodes of Mayday / Air Crash Investigation on YouTube.

Seeing some really stupid stuff.

Like: air traffic control centers - more than one - with just exactly enough staff to handle normal traffic, under normal conditions, properly... assuming no one ever takes a potty break. Any complications, and they're overloaded.

And then there's the lack of redundancy in aircraft systems. We've all heard the propaganda about how totally redundant everything is, and how critical electronic systems are supposed to be not only triply redundant but from multiple vendors so that a shared design flaw won't take out all three systems, and, and....

Well, having worked for a while in the telco-electronics space, and having seen the standards for redundancy in big-name central offices, where even a momentary disruption of message traffic is considered completely unacceptable, I tend to freak out when looking at how airplanes are wired.

A few years ago, I read the tale of an early 50s jet fighter lost in the dark with no radio and only minimal (vacuum-powered, no electricity needed) instruments after a single short circuit took out the entire electrical system.

Then I happened to look at the wiring diagram for a popular modern light plane. No redundancy! One short, or one loose wire, and you lose your radio and all electrically-powered instruments.

But surely airliners...?

Nope.

Thoroughly modern airliner lost after a fire in a single electronics compartment (shared between critical systems and entertainment systems) knocks out all the instruments. OK, so the fire was another factor in the crash, but losing all the fancy flight electronics on an airliner because of a single, localized fire?

And: slightly less modern airliner runs out of gas. Engines stop turning. Cabin lights go out: fine. Navigation and communication go out: WTF? You mean there's no battery backup for nav & comm? Probably no backup for the powered actuators, either (which take a darn sight more power than the electronics)? Not even a RAT?

Yikes.

Update: yet more instances of electricity and
hydraulic pressure being lost because the engines stop. A thought: why
the smeg can't the APU be started in flight? And, perhaps, be provided
with its own little reserve fuel tank good for maybe half an hour?

Johnny has thirty apples. The other children have one apple each. I take away fifteen of Johnny's apples. How many apples did I give Johnny?

(A) Fifteen, because that which is not taken is given.(B) Fourteen, because he's entitled to one.(C) You didn't give him anything, you idiot! You only took from him!

If you answered (C), you're clearly a heartless right-wing lunatic and probably an Objectivist. Report to the re-education camp immediately.

Now let's examine how this exercise works in the real world.

I take away fifteen of Johnny's apples on behalf of the collective. Johnny voluntarily gives me, personally, two of his remaining apples. I strongarm the other children into giving one apple each to Johnny to reward his civic-mindedness. I then divide the fifteen apples of the collective among the children, giving half an apple to each of the 29 now-appleless ones and keeping the remaining half-apple for myself in payment for my services.

Note that I didn't give Johnny anything in this scenario... never mind that he now has twelve more apples than he started with.

Four more years of gangster government, unfettered crony corporatism, tax farming, and the rapidly-escalating National Security State.

And it's not like Mittens could articulate why these are bad things. Or that they're bad things. Does he even understand? Does anyone high up in either big party understand?

Hey, look at the bright side. Maybe when the details of Benghazi and/or Gunwalker come out, President Beeblebrox will be impeached. Er... leaving us with that-idiot-Biden. Great.

Ah, you pollyannas may say, but at least the Democrats will own the inevitable failure. Really? When have the Democrats ever owned a failure? Failure is always blamed on the insidious forces of Snowball, or simply redefined as success. (Yes, you've been living under a bridge and eating moldy cheese these past ten years, but the Government built that bridge and is benevolently distributing cheese for all! Think how much worse off you'd be without us!)

Tuesday, 06 November 2012

When I got in my car this morning, the odometer read 177600. Inspiring?

Mid-morning: ambled off toward polling place. Didn't see signs up. Looked at sample ballot: oh, they've moved it to the other side of the mega-block. So, more walking. Find an obstacle course; there's massive road construction going on just outside the mobile-home park where the polling place is.

Seems like a light turnout. Apart from the road construction, things seem to be going smoothly.

Strange thought: a couple of days ago, there came in the mail something purporting to be a Republican voter guide. Had most of the positions you'd expect. But! It endorsed reGovernor Moonbeam's tax increase. For realz? But... the Democrats insist that the tax increase has to be done by initiative, bypassing the legislature, because the token Republicans allowed in the legislature are agin it. Somehow, this makes no sense. False-flag mailing by the higher-tax crowd? Or perhaps both parties want the tax increase, neither wants to take responsibility for it, and so it goes on the ballot?

And, on that note, back to work. An Imperial bargeload* of work showed up in the last few days, most of it urgent**, and I need to dig my way out.

* 1 Imperial bargeload = 1.136 metric bargeloads.

** "I'm in the middle of fifteen things, all of them annoying." - S. Ivanova

After a sleep-deprived weekend, I ended up going to bed at 8 last night, and falling asleep immediately. Then being woken up a few minutes later by a political robot. Back to sleep. Phone. Repeat.

This is not good. Every time I'm woken up by a loud (or otherwise alarming) noise, I leap out of bed severely disoriented, with my heart racing.

Eventually dump the phone outside the bedroom and hope that my parents don't have any medical emergencies.

And so, after what turned out to be a long and fitful night, I ended up sleeping late this morning. But that won't keep me from ambling down to the polling place at 0700 to vote NO on just about everything!

(Seriously, the whole "voter initiative" thing has gone bonkers; we keep having "initiatives" placed there by the ruling party, which wants to raise our taxes but doesn't want to take responsibility for doing so. Instead, the Party announces that the legislature can't do its job because, and I quote, "the forces of Snowball have sabotaged the windmill," and then try to badger us into raising our own taxes.)

Sunday, 04 November 2012

The latest Netflick Joy sent away for is a TV show called Defying Gravity.

Impressive visuals... but it takes a lot of turning-off-the-brain.

Ten years ago: deadly Martian sandstorm! For Niven fans, the phrase "about as dangerous as an enraged caterpillar" springs inevitably to mind.

Current events: it seems that as a result of changing two Supreme Court justices, abortion has been absolutely outlawed, as have home pregnancy tests - as we all know, this follows automatically, with none of that pesky business about state-by-state legislation. Curiously, though, women are still allowed to wear shoes and fly spaceships.

I guess we can allow the handwaving explanation of how the floor attracts the special clothing.

In space: aside from the apparent inconsistency of controls for the outer door of the airlock - is it just a touchscreen button, or is there a physical lever involved? - well, let's see what else annoyed me on the way past, during the Venus-suit event.

Suit, pressurized to 5 atm, has a slow leak. Can we boost the pressure? No, that might make it leak faster! Wait, why would you want to boost the pressure anyway? If the air for boosting the pressure is available, can't you use that to stabilize the pressure at, say 0.5 atm?

Donner is pulling on the safety line to retrieve Zoe. He needs to speed up! Pull faster! Er... given the lack of friction, each tug should be faster than the one before. Braking, however, is problematic; she'll come crashing back into the airlock at the speed of his last pull, which may be excessive.

As the pressure drops from 5 atm to 0.5 atm, Zoe gets incoherent. It's nitrogen narcosis! And the bends! Now, let's get this straight... 5 atm is about equivalent to 170 feet of water, so, yes, if they were silly enough to pump up that suit with standard air, nitrogen narcosis while pressurized would be a serious problem. And, as pressure came down, the bends would become a problem. Both of which are excellent reasons that no competent space agency would use standard air for such a purpose. Also, the symptoms of the bends are very different from those of nitrogen narcosis, and surely by the time she starts babbling she should be out of narcosis and into screaming in pain.

Oh, and why were they testing the suit with high pressure inside and vacuum outside anyway? Why not go to 6 atm inside, and keep the airlock at 1 atm? And is that really a good test anyway, when what you're worried about is high pressure on the outside leaking in? All the seals and joints ought to have been designed for higher pressure on the outside, so reversing the situation seems likely to miss actual problems and cause gratuitous failures.

And then there's the whole business of the Mysterious Thing With Eldritch Powers. Is Pod 4 a portal that opens onto Mars? Is it a TARDIS that contains Mars? Or is it just a sort of Room 101? Or, perhaps, is the Thing the Venusian ambassador to Mars, hitching a ride home after millennia in the post-apocalyptic wasteland?

There were a bunch of other distractingly-wrong things, but I've already managed to forget most of them. DVD #2 should be showing up in a couple of days....

At least it's not as bad as Le Morte d'Arthur. That, I can't get more'n a couple of pages into without reaching for the history books to see just how wrong it's getting.

Update: I have now seen all there is of it. Unlike Firefly, there's really no need for a second season... or a first, for that matter.

Silly annoying distraction: they don't even handwave over the subject of FTL communication, which they must have, or the conversations with Earth would have annoying coffee breaks in them. (Besides which, what's with all the remote control? Shades of old Soviet spam-in-a-can. Except the astronauts have local controls for most stuff, only those can be overridden from Earth, and some critical routine functions seem to require calling on Mission Control to push the buttons.)

Then there's the whole system-wide Pokemon game...

A: Cut it into several pieces, and bury each on a different planet, moon, or asteroid.Q: How would you imprison an immortal being of unspeakable evil?

Seriously, if you have no clue what they are, where they came from, why they are where they are, or what will happen if they're brought together... hey, kids! Let's go trick-or-treating for large pieces of plutonium!

And then there's the utter dysfunctionality of, well, everyone, and the well-worn TV staple of "rewriting people's DNA", and the vast conspiracy that makes no sense whatsoever, and, ....

Apparently it was meant to become a 6-year soap opera, addressing (audience for soap operas) ⋃ (audience for science fiction), but somehow* ended up attracting only (audience for soap operas) ⋂ (audience for science fiction).

* Which could not, in any conceivable way, involve a brain-damaged concept and crappy writing.

Saturday, 03 November 2012

I have the feeling I'd seen this video before: an attempt at the Sikorsky Prize with a giant super-lightweight bottom-rotor quadcopter - a sort of Ekranocopter, or Caspian Gym Monster.

Somewhat predictably, there's a great challenge in getting the rotors out of ground effect - hey, why do you think they're on the bottom?

Also, there seems to have been no consideration given to controlling the thing, so naturally it drifts off station rather quickly. (For some reason, the guy sitting in it is given the title "pilot" when in fact he's merely the engine.)

A stabilization system would add a few pounds (mainly in actuators and bearings) and a bit of drag on drive system (assuming it's supposed to be all human-powered). That, and making the span even biggerer to stretch that ground effect for all it's worth, and a big dose of performance-enhancing drugs for the engine... and perhaps filling the gym with a xenon-oxygen blend... and perhaps the grand stunt could be pulled off?

Oh, here we go: story. Apparently I hadn't seen that particular video before; it just looks awfully familiar.

And, yes, it is supposed to be human-powered, so getting the Librarian to pedal the thing would be out of bounds.

Afterthought: actually, a control system need not weigh that much. Quadrotors are normally controlled by differential throttling, so it's merely necessary to have some mechanism for adjusting the relative speeds of the rotors. So, some sort of four-way CVT, of rather limited capability, should do the trick.